The present invention relates to a wire reinforced fabric stent and method of weaving. In the prior art, stents are known to be made of interwoven groups of filaments and having a compliant outer covering positioned thereover. U.S. Pat. No. 4,441,215 to Kaster discloses such a configuration. However, Kaster fails to teach or suggest a stent made of a compliant fabric having wire interwoven therewithin. Further, Kaster fails to teach or suggest a particular manner of weaving a stent as disclosed herein.
U.S. Pat. No. 5,718,159 describes a stent having structural strands and three dimensionally braided textile strands integrated together to form a tubular shape. The metal structural strands are heat treated to impart a selected nominal shape in lieu of an original nominal shape. The present inventive process employs two dimensional braiding and there is no need to impart a selected nominal shape to the metal strands.
Applicant is also aware of U.S. Pat. No. 5,562,725 to Schmitt et al. that discloses a radially self-expanding implantable intraluminal device wherein the stent is described as a tubular braid formed from two sets of yarns spiraling in opposing directions about a longitudinal axis of the tube being formed. Schmitt et al. fail to teach the particular interrelationship of reinforcing wire and yarn nor the specific method of weaving disclosed herein.
U.S. Pat. No. 5,178,159 describes a three dimensional braiding process for making a stent having concentric sets of helically wound thread or wire elements. This patent does not describe two dimensional braiding.
A problem in the case of prior art stents made only of wire is that the stent migrates into the vessel wall over a period of time. In an attempt to remedy this situation stents combining wire and textiles have been created. However, such stents in the prior art have ratios of wire to fabric that do not optimize elasticity and axial elongation in the completed stent.